SYNTHESIS AND PROPERTIES OF AROMATIC POLYAMIDES DERIVED FROM 2,6-BIS(4-AMINOPHENOXY)NAPHTHALENE AND VARIOUS AROMATIC DICARBOXYLIC-ACIDS

2,6-Bis(4-aminophenoxy) naphthalene (2,6-BAPON) was synthesized in two steps from the condensation of 2,6-dihydroxynaphthalene with p-chloro nitrobenzene in the presence of potassium carbonate, giving 2,6-bis(4- nitrophenoxy) naphthalene, followed by hydrazine hydrate/Pd-C reductio n. A series of new polyamides were synthesized by the direct polyconde nsation of 2,6-BAPON with various aromatic dicarboxylic acids in the N -methyl-2-pyrrolidone (NMP) solution containing dissolved metal salts such as CaCl2 or LiCl using triphenyl phosphite and pyridine as conden sing agents. The polymers were obtained in quantitative yields with in herent viscosities of 0.62-2.50 dL/g. Most of the polymers were solubl e in aprotic dipolar solvents such as N,N-dimethylacetamide (DMAc) and NMP, and they could be solution cast into transparent, flexible, and tough films. The casting films had yield strengths of 84-105 MPa, tens ile strengths of 68-95 MPa, elongations at break of 8-36%, and tensile moduli of 1.4-2.1 GPa. The glass transition temperatures of the polya mides were in the range 155-225 degrees C, and their 10% weight loss t emperatures were above 505 degrees C in nitrogen and above 474 degrees C in air. (C) 1997 John Wiley & Sons, Inc.